Folds:

1. g.1: Insulin-like [56993] (1 superfamily) nearly all-alpha can be classified as disulphide-rich

2. g.2: Toxic hairpin [57006] (2 superfamilies) disulphide crosslinked alpha-helical hairpin

3. g.3: Knottins (small inhibitors, toxins, lectins) [57015] (18 superfamilies) disulphide-bound fold; contains beta-hairpin with two adjacent disulphides

4. g.4: PMP inhibitors [57282] (1 superfamily) disulphide-rich fold; all-beta: 3 antiparallel strands

5. g.5: Midkine [57287] (1 superfamily) disulphide-rich fold; all-beta: 3 antiparallel strands

6. g.6: Amb V allergen [57295] (1 superfamily) disulphide-rich; alpha+beta: 3 antiparallel strands followed by a short alpha helix

7. g.7: Snake toxin-like [57301] (1 superfamily) disulphide-rich fold: nearly all-beta

8. g.8: BPTI-like [57361] (1 superfamily) disulphide-rich alpha+beta fold

9. g.9: Defensin-like [57391] (1 superfamily) Disulphide-rich fold, nearly all-beta

10. g.10: Hairpin loop containing domain-like [57413] (1 superfamily) alpha+beta fold with two crossing loops

11. g.11: Neurotoxin III (ATX III) [57418] (1 superfamily) disulphide-rich fold

12. g.12: LDL receptor-like module [57423] (1 superfamily) disulphide-rich calcium-binding fold

13. g.13: Crambin-like [57428] (1 superfamily) disulphide-rich alpha+beta fold

14. g.14: Kringle-like [57439] (1 superfamily) disulphide-rich fold; nearly all-beta

15. g.15: Ovomucoid/PCI-1 like inhibitors [57466] (1 superfamily) disulphide-rich small alpha+beta fold

16. g.16: Trefoil [57491] (1 superfamily) disulphide-rich fold; duplication: consists of two homologous domains

17. g.17: Cystine-knot cytokines [57500] (1 superfamily) disulphide-rich fold; common core is all-beta

18. g.18: Complement control module/SCR domain [57534] (1 superfamily) disulphide-rich all-beta fold

19. g.19: Sea anemone toxin k [57545] (1 superfamily) disulphide-rich all-alpha fold

20. g.20: Blood coagulation inhibitor (disintegrin) [57551] (1 superfamily) small disulphide-rich

21. g.21: Methylamine dehydrogenase, L chain [57560] (1 superfamily) disulphide-rich; nearly all-beta

22. g.22: Serine proterase inhibitors [57566] (1 superfamily) disulphide-rich; nearly all-beta

23. g.23: TB module/8-cys domain [57580] (1 superfamily) disulphide-rich; alpha+beta

24. g.24: TNF receptor-like [57585] (1 superfamily) duplication: consists of three similar disulphide-rich domains

25. g.25: Heparin-binding domain from vascular endothelial growth factor [57592] (1 superfamily) duplication: consists of two similar disulphide-rich domains, alpha+beta

26. g.26: Antifungal protein (AGAFP) [57597] (1 superfamily) disulphide-rich; all-beta: open barrel, 5 strands; OB-fold-like

27. g.27: Fibronectin type I module [57602] (1 superfamily) disulphide-rich, all-beta

28. g.28: Thyroglobulin type-1 domain [57609] (1 superfamily) disulphide-rich, alpha+beta

29. g.29: Type X cellulose binding domain, CBDX [57614] (1 superfamily) disulphide-rich, alpha+beta

30. g.30: Carboxypeptidase inhibitor [57619] (1 superfamily) disulphide-rich, alpha+beta

31. g.31: nvertebrate chitin-binding proteins [57624] (1 superfamily) disulphide-rich

32. g.32: GLA-domain [57629] (1 superfamily) Calcium ion-bound

33. g.33: Cholecystokinin A receptor, N-domain [57641] (1 superfamily) a few helical turns and a disulide-crosslinked loop

34. g.34: HIV-1 VPU cytoplasmic domain [57646] (1 superfamily) a few helical turns assembled without a hydrophobic core?

35. g.35: HIPIP (high potential iron protein) [57651] (1 superfamily) folds around 4Fe-4S cluster

36. g.36: Ferredoxin thioredoxin reductase (FTR), catalytic beta chain [57661] (1 superfamily) folds around 4Fe-4S cluster

37. g.37: C2H2 and C2HC zinc fingers [57666] (1 superfamily) alpha+beta metal(zinc)-bound fold: beta-hairpin + alpha-helix

38. g.38: Zn2/Cys6 DNA-binding domain [57700] (1 superfamily) all-alpha dimetal(zinc)-bound fold

39. g.39: Glucocorticoid receptor-like (DNA-binding domain) [57715] (1 superfamily) alpha+beta metal(zinc)-bound fold

40. g.40: Retrovirus zinc finger-like domains [57755] (1 superfamily) metal(zinc)-bound fold

41. g.41: Rubredoxin-like [57769] (12 superfamilies) metal(zinc or iron)-bound fold; sequence contains two CX(n)C motifs, in most cases n = 2

42. g.42: Ribosomal protein L36 [57839] (1 superfamily) zinc-bound beta-ribbon motif

43. g.43: B-box zinc-binding domain [57844] (1 superfamily) zinc-bound alpha+beta motif

44. g.44: RING/U-box [57849] (1 superfamily) dimetal(zinc)-bound alpha+beta motif; structurally diverse

45. g.45: Pyk2-associated protein beta ARF-GAP domain [57862] (1 superfamily) zinc-bound alpha+beta motif

46. g.46: Metallothionein [57867] (1 superfamily) metal(iron)-bound fold duplication: consists of clear structural/sequence repeats

47. g.47: Zinc domain conserved in yeast copper-regulated transcription factors [57878] (1 superfamily) metal(zinc)-bound alpha+beta fold

48. g.48: Ada DNA repair protein, N-terminal domain (N-Ada 10) [57883] (1 superfamily) metal(zinc)-bound alpha+beta fold

49. g.49: Cysteine-rich domain [57888] (1 superfamily) dimetal(zinc)-bound alpha+beta fold

50. g.50: FYVE/PHD zinc finger [57902] (1 superfamily) dimetal(zinc)-bound alpha+beta fold

51. g.51: Zn-binding domains of ADDBP [57916] (1 superfamily) metal(zinc)-bound alpha+beta fold

52. g.52: Inhibitor of apoptosis (IAP) repeat [57923] (1 superfamily) metal(zinc)-bound alpha+beta fold

53. g.53: TAZ domain [57932] (1 superfamily) all-alpha fold; Zn-binding sites are in the loops connecting helices

54. g.54: Cysteine-rich domain of the chaperone protein DnaJ. [57937] (1 superfamily) metal(zinc)-bound extended beta-hairpin fold

55. g.55: Cellulose docking domain, dockering [64570] (1 superfamily) disulphide-rich, alpha+beta

56. g.57: Serine proteinase inhibitor lekti [69958] (1 superfamily) disulphide-rich, alpha+beta

57. g.58: Pheromone ER-23 [69963] (1 superfamily) disulphide-rich, all-alpha

58. g.59: Zinc-binding domain of translation initiation factor 2 beta [75688] (1 superfamily) zinc-bound beta-ribbon motif

59. g.60: TSP-1 type 1 repeat [82894] (1 superfamily) disulphide-rich fold; all-beta: 3 antiparallel strands

60. g.61: Apical membrane antigen 1 [82909] (1 superfamily) disulphide-rich, alpha+beta

61. g.62: Cysteine-rich DNA binding domain, (DM domain) [82926] (1 superfamily) alpha-helical fold with two Zn-binding sites

62. g.63: Mollusk pheromone [90182] (1 superfamily) disulphide-rich; all-alpha

63. g.64: Somatomedin B domain [90187] (1 superfamily) disulphide-rich

64. g.65: Notch domain [90192] (1 superfamily) disulphide-rich; all-alpha; calcium-binding

65. g.66: CCCH zinc finger [90228] (1 superfamily) metal(zinc)-bound alpha+beta fold

66. g.67: Zinc finger domain of DNA polymerase-alpha [90233] (1 superfamily) Zn-binding, all-alpha fold

More info for Class g: Small proteins

Timeline for Class g: Small proteins:

• Class g: Small proteins first appeared (with stable ids) in SCOP 1.55
  
• Class g: Small proteins appears in SCOP 1.63
  
• Class g: Small proteins appears in SCOP 1.67
  
• Class g: Small proteins appears in the current release, SCOPe 2.08